What is Participatory Modelling?

Gray et al (2018) “The field of PM lies at the intersection of participatory approaches to planning, computational modeling, and environmental modeling”

Wikipedia: “Participatory modeling is a purposeful learning process for action that engages the implicit and explicit knowledge of stakeholders to create formalized and shared representation(s) of reality. In this process, the participants co-formulate the problem and use modeling practices to aid in the description, solution, and decision-making actions of the group. Participatory modeling is often used in environmental and resource management contexts. It can be described as engaging non-scientists in the scientific process. The participants structure the problem, describe the system, create a computer model of the system, use the model to test policy interventions, and propose one or more solutions. Participatory modeling is often used in natural resources management, such as forests or water.

There are numerous benefits from this type of modeling, including a high degree of ownership and motivation towards change for the people involved in the modeling process. There are two approaches which provide highly different goals for the modeling; continuous modeling and conference modeling.

Abstract: Computational models are increasingly being used to assist in developing, implementing and evaluating public policy. This paper reports on the experience of the authors in designing and using computational models of public policy (‘policy models’, for short). The paper considers the role of computational models in policy making, and some of the challenges that need to be overcome if policy models are to make an effective contribution. It suggests that policy models can have an important place in the policy process because they could allow policy makers to experiment in a virtual world, and have many advantages compared with randomised control trials and policy pilots. The paper then summarises some general lessons that can be extracted from the authors’ experience with policy modelling. These general lessons include the observation that ofen the main benefit of designing and using a model is that it provides an understanding of the policy domain, rather than the numbers it generates; that care needs to be taken that models are designed at an appropriate level of abstraction; that although appropriate data for calibration and validation may sometimes be in short supply, modelling is ofen still valuable; that modelling collaboratively and involving a range of stakeholders from the outset increases the likelihood that the model will be used and will be fit for purpose; that attention needs to be paid to effective communication between modellers and stakeholders; and that modelling for public policy involves ethical issues that need careful consideration. The paper concludes that policy modelling will continue to grow in importance as a component of public policy making processes, but if its potential is to be fully realised, there will need to be a melding of the cultures of computational modelling and policy making.

Selected quotes: For these reasons, the ability to make ‘point predictions’, i.e. forecasts of specific values at a specific time in the future, is rarely possible. More possible is a prediction that some event will or will not take place, or qualitative statements about the type or direction of change of values. Understanding what sort of unexpected outcomes
can emerge and something of the nature of how these arise also helps design policies that can be responsive to unexpected outcomes when they do arise. It can be particularly helpful in changing environments to use the model to explore what might happen under a range of possible, but dfferent, potential futures – without any commitment about which of these may eventually transpire. Even more valuable is a finding that the model shows that certain outcomes could not be achieved given the assumptions of the model. An example of this is the use of a whole system energy model to develop scenarios that meet the decarbonisation goals set by the EU for 2050 (see, for example, RAENG 2015.)

Rick Davies comment: A concise and very informative summary with many useful references. Definitely worth reading! I like the big emphasis on the need for ongoing collaboration and communication between model developers and their clients and other model stakeholders However, I would have liked to see some discussion of the pros and cons of different approaches to modeling e.g. agent-based models vs Fuzzy Cognitive Mapping and other approaches. Not just examples of different modelling applications, useful as they were.

“This lecture will summarise the main points of a paper of the same name. That paper looks at the technical issues associated with the representation of Theories of Change and the implications of design choices for the evaluability of those theories. The focus is on the description of connections between events, rather the events themselves, because this is seen as a widespread design weakness. Using examples and evidence from a range of Internet sources six structural problems are described, along with their consequences for evaluation. The paper then outlines six different ways of addressing these problems, which could be used by programme designers and by evaluators. These solutions range from simple to follow advice on designing more adequate diagrams, to the use of specialist software for the manipulation of much more complex static and dynamic network models. The paper concludes with some caution, speculating on why the design problems are so endemic but also pointing a way forward. Three strands of work are identified that CEDIL and DFID could invest in to develop solutions identified in the paper.”

The paper referred to in the lecture was commissioned by CEDIL and is now pending publication in a special issue of an evaluation journal

Publisher blurb: “‘Correlation does not imply causation.’ This mantra was invoked by scientists for decades in order to avoid taking positions as to whether one thing caused another, such as smoking and cancer and carbon dioxide and global warming. But today, that taboo is dead. The causal revolution, sparked by world-renowned computer scientist Judea Pearl and his colleagues, has cut through a century of confusion and placed cause and effect on a firm scientific basis. Now, Pearl and science journalist Dana Mackenzie explain causal thinking to general readers for the first time, showing how it allows us to explore the world that is and the worlds that could have been. It is the essence of human and artificial intelligence. And just as Pearl’s discoveries have enabled machines to think better, The Book of Why explains how we can think better.

as described in this very readable article by David Owen:Customer Satisfaction at the Push of a Button – HappyOrNot terminals look simple, but the information they gather is revelatory. New Yorker, 2 February 2018, pages 26-29

Rick Davies comment: I like the design of the simple experiment described in the first para of this article. Because the locations of the petrol stations were different, and thus not comparable, the managers swapped the “treatment” given to each station i.e the staff they thought were making a difference to the performance of these stations.

by Caryn Peiffer and Rosita Armytage, April 2018, Development Leadership Program Research Paper 52. Available as pdf

Summary: Increasingly, development scholars and practitioners are reaching for exceptional examples of positive change to better understand how developmental progress occurs. These are often referred to as ‘positive outliers’, but also ‘positive deviants’ and ‘pockets of effectiveness’.
Studies in this literature promise to identify and examine positive developmental change occurring in otherwise poorly governed states. However, to identify success stories, such research largely relies on cases’ reputations, and, by doing so, overlooks cases that have not yet garnered a reputation for their developmental progress.

This paper presents a novel three-stage methodology for identifying and examining positive outlier cases that does not rely solely on reputations. It therefore promises to uncover ‘hidden’ cases of developmental progress as
well as those that have been recognised.

The utility of the methodology is demonstrated through its use in uncovering two country case studies in which surprising rates of bribery reduction occurred, though the methodology has much broader applicability. The advantage of the methodology is validated by the fact that, in both of the cases identified, the reductions in bribery that occurred were largely previously unrecognised.

Rick Davies comment: This is a paper that has been waiting to be published, one that unites a qual and quant approach to identifying AND understanding positive deviance / positive outliers [I do prefer the latter term, promoted by the authors of this paper]

The authors use regression analysis to identify statistical outliers, which is appropriate where numerical data is available.. Where the data is binary/categorical is possible to use other methods to identify such outliers. See this page on the use of the EvaLC3 Excel app to find positive outliers in binary data sets.

Sometimes, finding nothing at all can unlock the secrets of the universe. Consider this story from astronomy, recounted by Lily Zhao: “In 1823, Heinrich Wilhelm Olbers gazed up and wondered not about the stars, but about the darkness between them, asking why the sky is dark at night. If we assume a universe that is infinite, uniform and unchanging, then our line of sight should land on a star no matter where we look. For instance, imagine you are in a forest that stretches around you with no end. Then, in every direction you turn, you will eventually see a tree. Like trees in a never-ending forest, we should similarly be able to see stars in every direction, lighting up the night sky as bright as if were day. The fact that we don’t indicates that the universe either is not infinite, is not uniform, or is somehow changing.”

What can “finding nothing” – statistically insignificant results – tell us in economics? In his breezy personal essay, MIT economist Alberto Abadie makes the case that statistically insignificant results are at least as interesting as significant ones. You can see excerpts of his piece below.

In case it’s not obvious from the above, one of Abadie’s key points (in a deeply reductive nutshell) is that results are interesting if they change what we believe (or “update our priors”). With most public policy interventions, there is no reason that the expected impact would be zero. So there is no reason that the only finding that should change our beliefs is a non-zero finding.

Indeed, a quick review of popular papers (crowdsourced from Twitter) with key results that are statistically insignificantly different from zero showed that the vast majority showed an insignificant result in a context where many readers would expect a positive result.
For example…

You think people born on Friday the 13th are unlucky? Think again! (Cesarini et al., Kyklos, 2015)

It also doesn’t hurt if people’s expectations are fomented by active political debate.

Do you believe that cutting taxes on individual dividends will increase corporate investment? Better luck next time! (Yagan, AER, 2015)

Do you believe that Mexican migrant agricultural laborers drive down wages for U.S. workers? We think not! (Clemens, Lewis, & Postel, AER, forthcoming)

Okay, maybe not the Mexicans. But what about Cuban immigrants? Nope! (Card, Industrial and Labor Relations Review, 1980)

In cases where you wouldn’t expect readers to have a strong prior, papers sometimes play up a methodological angle.

Do you believe that funding community projects in Sierra Leone will improve community institutions? No strong feelings? It didn’t. But we had a pre-analysis plan which proves we aren’t cherry picking among a thousand outcomes, like some other paper on this topic might do. (Casey, Glennerster, & Miguel, QJE, 2012)

Do you think that putting flipcharts in schools in Kenya improves student learning? What, you don’t really have an opinion about that? Well, they don’t. And we provide a nice demonstration that a prospective randomized-controlled trial can totally flip the results of a retrospective analysis. (Glewwe et al., JDE, 2004)

Sometimes, when reporting a statistically insignificant result, authors take special care to highlight what they can rule out.

“We find no evidence that wealth impacts mortality or health care utilization… Our estimates allow us to rule out effects on 10-year mortality one sixth as largeas the cross-sectional wealth-mortality gradient.” In other words, we can rule out even a pretty small effect. “The effects on most other child outcomes, including drug consumption, scholastic performance, and skills, can usually be bounded to a tight interval around zero.” (Cesarini et al., QJE, 2016)

“We estimate insignificant effects of the [Swedish education] reform [that increased years of compulsory schooling] on mortality in the affected cohort. From the confidence intervals, we can rule out effects larger than 1–1.4 months of increased life expectancy.” (Meghir, Palme, & Simeonova, AEJ: Applied, 2018)

Of course, not all insignificant results are created equal. In the design of a research project, data that illuminates what kind of statistically insignificant result you have can help. Consider five (non-exhaustive) potential reasons for an insignificant result proposed by Glewwe and Muralidharan (and summarized in my blog post on their paper, which I adapt below).

The intervention doesn’t work. (This is the easiest conclusion, but it’s often the wrong one.)

The intervention was implemented poorly. Textbooks in Sierra Leone made it to schools but never got distributed to students (Sabarwal et al. 2014).

The intervention led to substitution away from program inputs by other actors. School grants in India lost their impact in the second year when households lowered their education spending to compensate (Das et al. 2013).

The intervention works for some participants, but it doesn’t alleviate a binding constraint for the average participant. English language textbooks in rural Kenya only benefitted the top students, who were the only ones who could read them (Glewwe et al. 2009).

The intervention will only work with complementary interventions. School grants in Tanzania only worked when complemented with teacher performance pay (Mbiti et al. 2014).

Here are two papers that – just in the abstract – demonstrate detective work to understand what’s going on behind their insignificant results.

For example #1, in Atkin et al. (QJE, 2017), few soccer ball producing firms in Pakistan take up a technology that reduces waste. Why?

“We hypothesize that an important reason for the lack of adoption is a misalignment of incentives within firms: the key employees (cutters and printers) are typically paid piece rates, with no incentive to reduce waste, and the new technology slows them down, at least initially. Fearing reductions in their effective wage, employees resist adoption in various ways, including by misinforming owners about the value of the technology.”

And then, they implemented a second experiment to test the hypothesis.

“To investigate this hypothesis, we implemented a second experiment among the firms that originally received the technology: we offered one cutter and one printer per firm a lump-sum payment, approximately a month’s earnings, conditional on demonstrating competence in using the technology in the presence of the owner. This incentive payment, small from the point of view of the firm, had a significant positive effect on adoption.”

Wow! You thought we had a null result, but by the end of the abstract, we produced a statistically significant result!

For example #2, Michalopoulos and Papaioannou (QJE, 2014) can’t run a follow-up experiment because they’re looking at the partition of African ethnic groups by political boundaries imposed half a century ago. “We show that differences in countrywide institutional structures across the national border do not explain within-ethnicity differences in economic performance.” What? Do institutions not matter? Need we rethink everything we learned from Why Nations Fail? Oh ho, the “average noneffect…masks considerable heterogeneity.” This is a version of Reason 4 from Glewwe and Muralidharan above.

These papers remind us that economists need to be detectives as well as plumbers, especially in the context of insignificant results.

Towards the end of the paper that began this post, Abadie writes that “we advocate a visible reporting and discussion of non-significant results in empirical practice.” I agree. Non-significant results can change our minds. They can teach us. But authors have to do the work to show readers what they should learn. And editors and reviewers need to be open to it.

“There has been an enormous increase in interest in the use of evidence for public policymaking, but the vast majority of work on the subject has failed to engage with the political nature of decision making and how this influences the ways in which evidence will be used (or misused) within political areas. This book provides new insights into the nature of political bias with regards to evidence and critically considers what an ‘improved’ use of evidence would look like from a policymaking perspective”

“Part I describes the great potential for evidence to help achieve social goals, as well as the challenges raised by the political nature of policymaking. It explores the concern of evidence advocates that political interests drive the misuse or manipulation of evidence, as well as counter-concerns of critical policy scholars about how appeals to ‘evidence-based policy’ can depoliticise political debates. Both concerns reflect forms of bias – the first representing technical bias, whereby evidence use violates principles of scientific best practice, and the second representing issue bias in how appeals to evidence can shift political debates to particular questions or marginalise policy-relevant social concerns”

“Part II then draws on the fields of policy studies and cognitive psychology to understand the origins and mechanisms of both forms of bias in relation to political interests and values. It illustrates how such biases are not only common, but can be much more predictable once we recognise their origins and manifestations in policy arenas”

“Finally, Part III discusses ways to move forward for those seeking to improve the use of evidence in public policymaking. It explores what constitutes ‘good evidence for policy’, as well as the ‘good use of evidence’ within policy processes, and considers how to build evidence-advisory institutions that embed key principles of both scientific good practice and democratic representation. Taken as a whole, the approach promoted is termed the ‘good governance of evidence’ – a concept that represents the use of rigorous, systematic and technically valid pieces of evidence within decision-making processes that are representative of, and accountable to, populations served”

Contents
Part I: Evidence-based policymaking – opportunities and challenges
Chapter 1. Introduction
Chapter 2. Evidence-based policymaking – an important first step, and the need to take the next
Part II: The politics of evidence
Chapter 3. Bias and the politics of evidence
Chapter 4. The overt politics of evidence – bias and the pursuit of political interests
Chapter 5. The subtle politics of evidence – the cognitive-political origins of bias
Part III: Towards the good governance of evidence
Chapter 6. What is ‘good evidence for policy’? From hierarchies to appropriate evidence.
Chapter 7. What is the ‘good use of evidence’ for policy?
Chapter 8. From evidence-based policy to the good governance of evidence

Abstract: In the social sciences, there is a longstanding tension between data collection methods that facilitate quantification and those that are open to unanticipated information. Advances in technology now enable new, hybrid methods that combine some of the benefits of both approaches. Drawing inspiration from online information aggregation systems like Wikipedia and from traditional survey research, we propose a new class of research instruments called wiki surveys. Just as Wikipedia evolves over time based on contributions from participants, we envision an evolving survey driven by contributions from respondents. We develop three general principles that underlie wiki surveys: they should be greedy, collaborative, and adaptive. Building on these principles, we develop methods for data collection and data analysis for one type of wiki survey, a pairwise wiki survey. Using two proof-of-concept case studies involving our free and open-source website www.allourideas.org, we show that pairwise wiki surveys can yield insights that would be difficult to obtain with other methods.